1. Field of the Invention
The present invention relates to the healing of wounds. More particularly, the invention relates to a vacuum assisted wound closure system wherein a foam pad is modified to facilitate wound healing by including phototherapy compatible optical fibers.
2. Background of the Invention
Wound closure involves the inward migration of epithelial and subcutaneous tissue adjacent the wound. This migration is ordinarily assisted through the inflammatory process, whereby blood flow is increased and various functional cell types are activated. Through the inflammatory process, blood flow through damaged or broken vessels is stopped by capillary level occlusion, whereafter cleanup and rebuilding operations may begin. Unfortunately, this process is hampered when a wound is large or has become infected. In such wounds, a zone of stasis (i.e. an area in which localized swelling of tissue restricts the flow of blood to the tissues) forms near the surface of the wound.
Without sufficient blood flow, the epithelial and subcutaneous tissues surrounding the wound not only receive diminished oxygen and nutrients, but are also less able to successfully fight bacterial infection and thus are less able to naturally close the wound. Until recently, such difficult wounds were addressed only through the use of sutures or staples. Although still widely practiced and often effective, such mechanical closure techniques suffer a major disadvantage in that they produce tension on the skin tissue adjacent the wound. In particular, the tensile force required in order to achieve closure using sutures or staples causes very high localized stresses at the suture or staple insertion point. These stresses commonly result in the rupture of the tissue at the insertion points, which can eventually cause wound dehiscence and additional tissue loss.
Additionally, some wounds harden and inflame to such a degree due to infection that closure by stapling or suturing is not feasible. Wounds not reparable by suturing or stapling generally require prolonged hospitalization, with its attendant high cost, and major surgical procedures, such as grafts of surrounding tissues. Examples of wounds not readily treatable with staples or suturing include large, deep, open wounds; decubitus ulcers; ulcers resulting from chronic osteomyelitis; and partial thickness burns that subsequently develop into full thickness burns.
As a result of these and other shortcomings of mechanical closure devices, methods and apparatus for draining wounds by applying continuous negative pressures have been developed. When applied over a sufficient area of the wound, such negative pressures have been found to promote the migration toward the wound of epithelial and subcutaneous tissues. In practice, the application to a wound of negative gauge pressure, commercialized by Applicant under the designation “Vacuum Assisted Closure” (or “V.A.C.”) therapy, typically involves the mechanical-like contraction of the wound with simultaneous removal of excess fluid. In this manner, VAC therapy augments the body's natural inflammatory process while alleviating many of the known intrinsic side effects, such as the production of edema caused by increased blood flow absent the necessary vascular structure for proper venous return.
While V.A.C.® therapy has been highly successful in the promotion of wound closure, healing many wounds previously thought largely untreatable, some difficulty remains. Because the very nature of V.A.C. therapy dictates an atmospherically sealed wound site, the therapy must often be performed to the exclusion of other beneficial, and therefore desirable, wound treatment modalities. One such excluded modality is phototherapy—a method for wound treatment wherein appropriate wavelengths of light are directed into or about the wound bed.
Phototherapy has to date been regarded as impossible or at least impracticable in combination with V.A.C. therapy due to the utilization of opaque materials in the administration of V.A.C. therapy. In particular, the use of an opaque foam pad for within the wound site, as is known to those of ordinary skill in the V.A.C.-related arts, requires that the V.A.C. therapy be disrupted and the dressings removed in order that phototherapy can be performed. Because phototherapy and the like are nonetheless desirable in combination with V.A.C. therapy, it is a primary object of the present invention to provide a V.A.C. therapy wound dressing that is compatible with such therapies.
It is a further object of the present invention to provide such a dressing that is also readily adaptable to a variety of wound sizes and shapes and that requires no inordinate modification of known procedures for or administration of V.A.C. therapy.
It is yet a further object of the present invention to provide such a dressing that is economical and disposable, but also safe for general patient use.